外源性雌激素及三苯氧胺对大鼠乳腺癌癌前期病变的作用

摘要

Objectiver　 To establish murine breast precancerous model and evaluate the effect of exogenous estrogen and tamoxifen.　 Method　 50 female Wistar rats were divided into contol group (n＝12), the other 38 received low dose carcinogen (DMBA) by gastrogavage, and then divided into DMBA group (common diet,n＝8); DMBA+DES group(DES added chow,n＝15); and DMBA+TAM group (TAM added chow,n＝15). 3 months later, the status of breast hyperplasia, AgNOR and DNA content were measured. 　Results　 All indexs in control group and DMBA+TAM group were normal.However,in DMBA group and DMBA+DES group,the breast hyperplasia rate was 75%, 93.3%, AgNOR was 3.71±0.76, 5.60±0.42, DNA was 88.59±7.17, 137.75±3.13 respectively.Compared with control group and DMBA+TAM group, the differences of indexes in DMBA and in DMBA+DES group were significant (P<0.01). 　Conclusion　 Low dosage DMBA administered by gastrogavage established breast precancerous model. Exogenous estrogen promotes the development of breast precancerous disease induced by DMBA, while TAM suppresses the canceration.%目的　建立乳腺癌癌前期病变动物模型，探索外源性雌激素（EE）及其拮抗剂的作用。　方法　Wistar雌性大鼠50只，对照组12只；其余大鼠经胃管灌注7，12-二甲基苯并蒽（DMBA），8只用正常饮料(DMBA组)；15只饲料中加乙烯雌酚(DMBA＋DES组)；15只饲料加三苯氧胺(DMBA＋TAM组)。3个月后检测乳腺增生、核仁形成区嗜银蛋白（AgNOR）和DNA含量。　结果　DMBA组和DMBA＋DES组的乳腺组织增生率分别为75％及93.33%;AgNOR计数为3.71±0.76及5.60±0.42;DNA含量为88.59±7.17及137.75±3.13，DMBA组及DMBA＋DES组与对照组和DMBA＋TAM组比较差异有显著意义（P＜0.01）。　结论　一次性灌注DMBA可以建立乳腺癌癌前期病变动物模型；EE可加重DMBA诱导的乳腺癌癌前期病变；而TAM则具有阻断作用。